/* Threads.c -- multithreading library
2017-06-26 : Igor Pavlov : Public domain */

#include "Precomp.h"

#ifndef UNDER_CE
#include <process.h>
#endif

#include "Threads.h"

static WRes GetError()
{
  DWORD res = GetLastError();
  return res ? (WRes)res : 1;
}

static WRes HandleToWRes(HANDLE h) { return (h != NULL) ? 0 : GetError(); }
static WRes BOOLToWRes(BOOL v) { return v ? 0 : GetError(); }

WRes HandlePtr_Close(HANDLE *p)
{
  if (*p != NULL)
  {
    if (!CloseHandle(*p))
      return GetError();
    *p = NULL;
  }
  return 0;
}

WRes Handle_WaitObject(HANDLE h) { return (WRes)WaitForSingleObject(h, INFINITE); }

WRes Thread_Create(CThread *p, THREAD_FUNC_TYPE func, LPVOID param)
{
  /* Windows Me/98/95: threadId parameter may not be NULL in _beginthreadex/CreateThread functions */
  
  #ifdef UNDER_CE
  
  DWORD threadId;
  *p = CreateThread(0, 0, func, param, 0, &threadId);

  #else

  unsigned threadId;
  *p = (HANDLE)_beginthreadex(NULL, 0, func, param, 0, &threadId);
   
  #endif

  /* maybe we must use errno here, but probably GetLastError() is also OK. */
  return HandleToWRes(*p);
}

static WRes Event_Create(CEvent *p, BOOL manualReset, int signaled)
{
  *p = CreateEvent(NULL, manualReset, (signaled ? TRUE : FALSE), NULL);
  return HandleToWRes(*p);
}

WRes Event_Set(CEvent *p) { return BOOLToWRes(SetEvent(*p)); }
WRes Event_Reset(CEvent *p) { return BOOLToWRes(ResetEvent(*p)); }

WRes ManualResetEvent_Create(CManualResetEvent *p, int signaled) { return Event_Create(p, TRUE, signaled); }
WRes AutoResetEvent_Create(CAutoResetEvent *p, int signaled) { return Event_Create(p, FALSE, signaled); }
WRes ManualResetEvent_CreateNotSignaled(CManualResetEvent *p) { return ManualResetEvent_Create(p, 0); }
WRes AutoResetEvent_CreateNotSignaled(CAutoResetEvent *p) { return AutoResetEvent_Create(p, 0); }


WRes Semaphore_Create(CSemaphore *p, UInt32 initCount, UInt32 maxCount)
{
  *p = CreateSemaphore(NULL, (LONG)initCount, (LONG)maxCount, NULL);
  return HandleToWRes(*p);
}

static WRes Semaphore_Release(CSemaphore *p, LONG releaseCount, LONG *previousCount)
  { return BOOLToWRes(ReleaseSemaphore(*p, releaseCount, previousCount)); }
WRes Semaphore_ReleaseN(CSemaphore *p, UInt32 num)
  { return Semaphore_Release(p, (LONG)num, NULL); }
WRes Semaphore_Release1(CSemaphore *p) { return Semaphore_ReleaseN(p, 1); }

WRes CriticalSection_Init(CCriticalSection *p)
{
  /* InitializeCriticalSection can raise only STATUS_NO_MEMORY exception */
  #ifdef _MSC_VER
  __try
  #endif
  {
    InitializeCriticalSection(p);
    /* InitializeCriticalSectionAndSpinCount(p, 0); */
  }
  #ifdef _MSC_VER
  __except (EXCEPTION_EXECUTE_HANDLER) { return 1; }
  #endif
  return 0;
}
